1. Field of the Invention
The present invention relates to a so-called cork chip moulding which is used as, for example, an insulator of an automobile dash board or of an automobile floor trim.
2. Description of the Prior Art
There is a proposal to use a so-called polyurethane chip lo moulding as the insulator for the above uses. The polyurethane chip moulding is made by mixing polyurethane foam chips with urethane prepolymer, and by curing the urethane prepolymer. The urethane prepolymer is transformed into polyurethane through this cure. In this moulding as a final product, the polyurethane foam chips are dispersed in or bound with the polyurethane. However, the thus obtained polyurethane chip moulding has the following drawbacks.
It is insufficient in sound insulation and in rigidity. Furthermore, it has a hygroscopic property, so that it tends to be deformed under a high temperature and high humidity condition.
There is another proposal to use a polyvinyl chloride sheet as the insulator of the dash board. This sheet is adhered to a substrate of the dash board. However, this sheet has the following drawbacks.
It is too heavy in weight and inferior in adhesion. Furthermore, there is a problem that a gap tends to be produced between the sheet and the substrate due to creep in the sheet under a certain condition.